Could a lens be designed such that the rear element always produces an image circle of 200mm, but the front elements could be swapped such that the angle of coverage goes from wide to tele? Or could a spacer tube for the front element or rear element change the focal point such that it would render a similar image circle?
I.e. a kit with effectively 65mm, 90mm, 135, 180, 250mm front elements with decreasing angle of views with same max aperature.

This would require one back element and one shutter.